Field of the Invention
The present application relates to a liquid composition and an etching method for etching a silicon substrate.
Description of the Related Art
For forming through holes and recesses in a silicon substrate, wet etching using a liquid composition can be applied. Japanese Patent Laid-Open No. 2010-278371 discloses a wet etching process using an alkaline organic compound and water.
In general, it takes a long time to etch a silicon substrate by a wet process. Shorter etching time is desirable. In addition, if the silicon substrate has a member made of an aluminum or aluminum alloy, such as a conductive line, the member should be prevented from being etched with a liquid composition. To deal with these issues, Japanese Patent Laid-Open No. 2009-206335 discloses an etching method in which a silicon substrate is etched with a liquid composition containing an alkaline organic compound and a silicon compound.